The art of subterranean wall surface preparation is, in general, silent to the cultivation of a wall surface, whereby it is conventional to use a precise cutting treatment comprising the use of, e.g., knives and chemically corrosive jets, or to use a non-intrusive scraping treatment that attempts to remove debris without damaging a wall surface with, e.g., lightly brushing, jetting or scraping with downhole well clean-up tools, or the convention can comprise the complete destruction of a wall surface using, e.g., explosives or milling. The present invention can, like the arts of agriculture and horticulture, use primary and secondary cultivation means that can be considered less precise and which do not attempt to destroy a wall surface within a subterranean well, though they may be used to weaken a wall surface in preparation for subsequent destruction.
Agriculture and horticulture use various arcuate engagement arrangements, e.g. ploughs, harrows, tillers and filament-like weed trimmers that can flexibly drag a member to scrape a surface and, e.g., spread substances, or form furrows or perform relatively rough but selectively limited cuts using a kinetic drag force focused by an arcuate path, arcuate shape and/or the concave sides of the furrow as it is deepened.
In a manner comparable to the agricultural or horticultural arts, subterranean wells and any debris therein can be cut, dug or tilled to remove or bury said debris or other debris or cables within a well like rocks are removed from soil or like weeds are cut and buried in soil. Cultivation can further comprise surface preparation other than cutting, digging or tillage. For example, like cultivation of a garden's soil surface, subterranean cultivation can comprise the application of a spreadable substance with a scraper member to dissolve, repair, grout and/or line a subterranean wall surface.
Like conventional cultivation, subterranean cultivation can comprise primary and/or secondary categories, wherein the primary category can comprise digging or furrowing into a wall surface, which itself can comprise various cutting, ploughing, harrowing or tillage means oriented longitudinally and/or transversely to the axis of a well or to a cultivating apparatus's hoistable shaft's axis. The second category can comprise, e.g., the placement of substances, chemicals or incendiaries upon a wall surface to change its structure for subsequent use.
Chemical compounds comprising, e.g., explosives, gelled fluids, acids, cements, resins and plastics or fibrous materials, can be applied to a subterranean wall surface during its cultivation, which is comparable to applying fertiliser, manure and lime during surface farming cultivation.
Cultivation of a subterranean wall surface can comprise, e.g., using acids to dissolve or fluid jets or incendiary devices, like explosives, to remove or bury debris within a well, whereas the agricultural form of cultivation may use chemical herbicides or incendiaries to “burn-down” and/or use weed trimmers to sever and kill weeds.
Cultivation of a subterranean wall surface can comprise a middle ground between the conventional propensities for precise cuts circumferentially around a wall surface that, generally, require a consistent surface material to avoid unacceptable vibration and/or burying of the cutter, or the complete destruction of the wall surface, wherein the present invention can perform the middle ground intrusive intervention into various materials comprising one or more wall surfaces simply and more cost effectively. For example, the downhole adaptation of, e.g., a weed trimmer apparatus equipped with a super abrasive filament-like scraping member to arcuately deploy and cut a dichotomy of bores', conduits' and cables' surfaces within a subterranean well using the rotated arc-shaped path of a flexible and arcuately engaged filament-like scraping member that can more effectively cut such surfaces, albeit with less precision across a selectively limited surface area focused by the concave sides of a deeper furrow with each subsequent pass of the scraping member.
Conventional and prior art downhole cutting can be divided between precision cuts and those which are not intended to be precise, wherein both are generally oriented transverse to the longitudinal axis of the well. Relatively precise downhole cuts can use, e.g., knife, explosive, chemical and/or abrasive grit cutters to, generally, target and affect a relatively narrow wall surface area for the purpose of, e.g., severance. Downhole cuts that are not precise can comprise, e.g., milling or explosives that, generally, target a single cut face and are intended to cut or abrade portions to destruct a large wall surface areas along a single cut face.
Conventional and prior art well bore cleaning can comprise cutting along the longitudinal axis to clean and remove debris from a wall surface while leaving the original wall surface relatively unaffected.
Conventional and prior art well bore cleaning and cutting can comprise, e.g., cutting and honing a polished bore receptacle (PBR) at the top of a liner for a tie-back seal stack mandrel and/or packer wherein the objective is to refurbish the original wall surface.
Conversely, cutting or scraping with a scraping member of the present invention can include: a first feature comprising, e.g., proximal axially longitudinal and/or proximal axially transverse cuts that can be comparable to furrows or, alternatively, e.g., conventionally shaped furrows that cut a surface and perforate through the opposite wall surface; and a second feature comprising, e.g., a scraper that urges or squeezes a spreadable substance into furrow cuts or perforations.
Methods and apparatus of the present invention can cultivate a subterranean wall surface, which is not conventionally practiced nor taught within prior art, to provide significant benefits. The references cited below, typical of prior art, generally pertain to surface treatment practices, that can be adapted according to the present invention, but which do not provide a system for cultivating a wall surface. The present invention can provide the additional benefit of using arcuately engaged scraper members to prepare a downhole surface for subsequent use, which can be usable with conventional wireline, slickline, coiled tubing and drill strings. Various exemplary prior art has been cited, wherein other unreferenced prior art can also be adapted by those skilled in the art of modification and/or practice who will appreciate that various modifications, additions and substitutions are possible, without departing from the scope and spirit of the invention as disclosed herein. To the extent possible, since applicable conventional practice and prior art do not exist for cultivating a subterranean wall surface, various exemplary prior art is discussed herein.
For example, prior art well surface treatment and apparatus, e.g. EP 1,416,118, U.S. Pat. No. 7,757,769, U.S. Pat. No. 7,861,787, U.S. Pat. No. 8,418,755, WO 2006/048210 and WO 2007/101444 teach the positioning of an apparatus, generally comprising a cutter, packer and/or jet nozzle, and the releasing of a substances into a region that can be cut, perforated or fractured, wherein prior art is silent to the need for arcuately extending and engaging a draggable cutter to cultivate a wall surface with kinetic drag force applied by a scraper member to prepare the wall surface for improved spreadable substance engagement, reagent operation and/or ancillary apparatus engagement.
Prior art, e.g. EP 1,790,779 B1, teaches large scale method and apparatus for trenching that are oversized for use within a well bore. Various prior art, e.g. EP 1,840,325B1 and WO 2005/052311, teach the application of a spreadable substance like cement and use agriculture terminology like “tilling the well with a metal casing” but are silent to the art of longitudinal furrowing, transverse furrowing with a filament-like cutter and/or forming a lattice of furrows to cultivate a wall surface.
Various prior art, e.g. U.S. Pat. No. 8,376,043 B2, U.S. Pat. No. 6,148,918, U.S. Pat. No. 7,559,374, U.S. Pat. No. 7,040,395, U.S. Pat. No. 7,997,354, U.S. Pat. No. 8,356,662 and WO 02/35055, can be adapted for use with the embodiments taught by the present disclosure, but said prior is generally silent to cultivation. Conventional practice and prior art has generally involved using filaments, springs, pistons and fluid jets engaged to a shaft or imbedded within a stabilizer blade that can be used to scrape a wall surface by cutting or jetting and removing engaged debris to “clean” the wall surface, but which are silent to cutting into and cultivating a wall surface and using the sides of a resulting furrow to further focus subsequent cutting to further deepen said furrow until it is a substantial concave cut. Other prior art, e.g. U.S. Pat. No. 6,494,272, use pistons with eccentric stabilizer blades for cutting or reaming of a wall surface to produce a substantially cylindrical wall surface plane, but which is silent to the forming, joining and/or reducing amplitude differences in a wall surface resulting from longitudinal and/or transverse cultivation of furrows.
Exemplary prior art cutters, e.g. US 2009/0308605, U.S. Pat. No. 7,631,702, US 2012/0193152 A1, U.S. Pat. No. 5,752,454, WO 96/28635, U.S. Pat. No. 7,575,056, U.S. Pat. No. 8,210,251, U.S. Pat. No. 7,588,101, U.S. Pat. No. 8,147,293, US 2008/0277118, US 2011/0053458 and WO 2004/092532, teach various milling arrangements, “harrowing” disks, “ploughing” cutters or casing shoes, “no-till” disk opening systems, cutting discs and/or jet cutting tools that seek to cut and destroy a portion of a surface and/or sever one wall surface from another to separate a wall completely, but these cutters do not use a furrow to further focus a cut using its concave sides or using a furrow to separate said wall into regions, wherein such prior art is silent to the need for less precise furrow concave shape guidance of longitudinal and/or transverse cultivating preparation of a wall surface to improve its subsequent use by an ancillary apparatus or spreadable substance.
Various prior art, e.g. U.S. Pat. No. 7,726,028 and WO 99/10675, teach the longitudinal cutting of a conduit or surface but are silent to arcuate downhole engagement of cutters to a wall surface so that said cutters can be flexibly engaged and be flexibly deflected from a wall surface to prevent, e.g., burying the cutters within the wall surface.
Other prior art, e.g. WO 93/19281 and WO 2009/121882, teaches the use of pivotal members for centralizing and stabilizing a milling or sealing assembly but are silent as to how a bascule-like pivotal arrangement can be deployed with scraping cutters within a relatively small diameter passageway and expanded into a significantly larger passageway, and wherein such prior art is also silent also to how a subterranean wall surface can be cultivated such that subsequent milling and/or sealing may become more effective.
Various exemplary prior art, e.g. EP 2,497,602 A1, describes super abrasive filaments that can be adapted for use with, e.g. U.S. Pat. No. 2,708,335, U.S. Pat. No. 4,926,557, U.S. Pat. No. 4,942,664, U.S. Pat. No. 7,966,736, U.S. Pat. No. 7,979,991, US 2011/0005185 and US 2012/0266705, and alternatively, other prior art, e.g. U.S. Pat. No. 6,052,907 and WO 2012/071636, includes the use of more rigid cutters in place of, e.g., flexible filament cutters; however, this prior art does not teach or disclose cutting or furrowing into a surface of a wall of a subterranean well bore, conduit and/or cable to form longitudinally aligned, overlapping and/or crossing furrows therein, which can be used to further separate a plane of said surface into a plurality of planes and associated separate surface regions for use by an ancillary apparatus or a spreadable substance engaged thereto.
Scraper member embodiments of the present invention may also be deployed using various arcuate linkages and devices described in the existing art, e.g. U.S. Pat. No. 5,575,333, U.S. Pat. No. 5,785,125, U.S. Pat. No. 7,090,007, U.S. Pat. No. 7,866,384 and U.S. Pat. No. D662,942, which can be adapted for use with the embodiments of the present invention.
Existing actuating devices that are suitable for downhole use, e.g. U.S. Pat. No. 4,762,179, U.S. Pat. No. 5,127,477 and US 2011/0232969, could be adapted for actuating and deactivating various embodiments of the present invention.
Various existing spreadable substances, e.g. EP 2,071,003 A1, U.S. Pat. No. 5,127,473, U.S. Pat. No. 7,325,603, can be adapted for use within the disclosed scope and spirit of the present invention. Various other prior art related to the application of a spreadable substance, e.g. US 2012/0285696, teaches an adaptable diameter deployable through conventional diameter changes that is silent to deployment through a very narrow passage with expansion to a substantially larger passage that can be adapted for use with various scraper member applications; whereby, these patents and applications do not teach or disclose the methods and apparatus of the present invention.
Other prior art, e.g. U.S. Pat. No. 6,116,344 and US 2013/0014957, teach side-tracking and make reference to a “harrow” application or provide means for re-entry into a side-track, but this prior art is silent to wall surface preparation prior to milling a side-track window and/or subsequent entry or re-entry into the side-track using a portion of a cultivating apparatus selectively arranged to be left downhole.
Prior art also teaches the use of filament wound material, fiberglass cloth wound material and composite plastics, e.g. US 2013/0048271, but is silent to the use of such materials within methods and apparatus of downhole cultivation to, e.g., provide a means of boring through a tool purposely disposed of downhole after initially being used to cultivate and/or scrap a spreadable substance across a wall surface to ensure its engagement.
Various component member parts of the present invention can include the use of such devices as disclosed in, e.g. US 2005/0205264, US 2007/0227735, US 2012/0061098 and WO 2005/027615, which can be adapted for use within methods and apparatus to provide benefit according to the scope and spirit of the present invention.
Prior art disclosures in, e.g., U.S. Pat. No. 6,478,093 B1 are silent to a species of longitudinal downhole cutters having a low complexity and low diameter to length ratio that falls within the larger genus of longitudinal cutting. In addition, the prior art is silent to axial string force driven downhole furrow cutting with long longitudinal cuts not generally practiced, albeit various disclosures of coupling and packer cutting lessons applicable to limited axial distances or disclosed drawings that can be superficially compared by those unskilled in cutting within the small dimensions of a downhole space or the need to provide member part thicknesses sufficient to withstand downhole forces.
Prior art addresses the splitting of a relatively short axial length of a conduit coupling and/or packer within larger well bore diameters, but is generally silent to a low complexity means of splitting long tubing lengths from within diameters smaller than a soft drink can.
Prior art U.S. Pat. No. 6,478,093 B1 teaches an apparatus and method for installing and removing packer assemblies from a subterranean well that primarily uses a chemically reactive longitudinal cutter device that is lowered into the well and activated by use of conventional wire line equipment. Alternatively, U.S. Pat. No. 8,322,422 B2 teaches a jetting tool, inside a tubular element, which effects a high-pressure fluid flow from the jetting tool to produce a longitudinal cut. Furthermore, U.S. Pat. No. 5,924,489 discloses a sloped cut line midway between a axial transverse and axial cut, while U.S. Pat. No. 2,407,991 and U.S. Pat. No. 5,720,344 disclose longitudinal explosive cutting apparatus and methods, and U.S. Pat. No. 4,396,065 teaches an electrical arc that is usable to provide an axial longitudinal cut. While the prior art may be applicable to short longitudinal cuts within large conduit diameters, they are generally too complex, if usable, to efficiently cut long lengths of small diameter tubing.
While drawings for a downhole tool usable in larger well bore diameters can be theoretically scaled down, in practice intricate components become too small to effectively machine and too weak to withstand the forces of cutting the quality of steel that can be used to contain the pressures of a subterranean well.
Generally, prior art is silent to the working space required by a cutter, whereby the body of commonly used American Petroleum Institute (API) specification 8.63 kilogram per meter (kg/m) or 5.8 pounds per foot (ppf) tubing has a 77.8-mm (3.063-in) radially outward upset coupling engaging a 60.33 millimeters (mm) or 2⅜ inch (in.) outside diameter and 47.4-mm (1.867-in) inside diameter tube body, which is smaller than the inside diameter of a common soft drink can.
The difficulty level of working within common production tubing is readily visualized using a United States (US) standard sized soft drink can, which is similar to soft drink cans worldwide, wherein a US soft drink can is 122.68-mm (4.83-in) in height, with a 54.1-mm (2.13-in) diameter at the lid, and a 66-mm (2.60-in) diameter at the widest part of the soft drink can body, wherein said soft drink can will not pass through API 73.03-mm (2.875-in), or smaller, tubing.
Rapidly rotating cutting wheel dimensions are taught in the U.S. Pat. No. 7,575,056 B2 lessons for a transverse tubing cutter, which is scaled to fit within, e.g., a conventional soft drink can's 54.1-mm (2.13-in.) diameter at its smallest longitudinally transverse dimension. Such lessons are, however, silent as to how such a transverse cutter could be turned to cut longitudinally because the diameter of the cutting wheel is marginally less than the diameter of cutting tool, whereby the diameter of a driven hinge arrangement would preclude disposing the cutting wheel longitudinally. The arrangement of U.S. Pat. No. 7,575,056 B2 can only just accommodate the motor and cutting wheel without including the drive hinge.
Due to limited downhole space, prior art generally favours the use of chemicals and explosives within smaller diameter tubing, while electrical motors and rotational cutters are favoured in larger diameters, wherein almost all prior art focuses on cutting transversely to the well's axis or transversely severing a conduit or transversely separating a conduit using a short longitudinal cut across a coupling or hanger/production packer to split the connect and release the conduit from its lower end engagement. For example, EP 2 530 238 B1 and WO 2012/164023 A1 teach a motor/pump actuated and motor rotated pivot arm that is used to provide a transverse axial cut that cannot be easily oriented to a longitudinal rotation or arranged to effectively use a filament cutter. Similar downwardly and laterally orientated and transversely rotated arrangements for an under reamer pivot arm are taught in U.S. Pat. No. 2,749,187 and US2013/0299248, A1 which are similar in configuration and orientation and, thus, similarly unsuitable.
The lessons in US 2010/0258289 A1 and US 2013/0241742 teach similar pivotal arm arrangements, but the applications are silent to the use of transversely rotated filaments and the provision of a pivot arm of sufficient strength to efficiently cut steel while fitting within, e.g., the transverse dimensions of a soft drink can sized tubing that can laterally expand to larger diameter surface casing surfaces.
For example, to cut the 6.45-mm (0.254-in) wall thickness of API 8.63-kg/m (5.8-ppf) tubing with a 60.33-mm (2⅜ in) outside diameter and 47.4-mm (1.867-in) inside diameter, all of the arrangements described in U.S. Pat. No. 6,478,093 B1 must fit through the tubing's inside diameter, which is 72% of the diameter of a soft drink can (47.4-mm/66-mm). The disclosed rapidly rotating cutting wheel would require a minimum diameter of 25.6-mm (1.008-in) if an axle diameter of 6.35-mm (0.25-in) is added to twice the pivot arm journal radius of 3.175-mm (0.125-in) and twice the cut wheel radius of 6.45-mm (0.254-in), which is necessary to secure the cutting wheel with sufficient cutting wheel depth to just cut through the tubing wall. Subtracting the cutting wheel diameter of 25.6-mm (1.008-in) from the tubing inside diameter of 47.4-mm (1.867-in) leaves 21.8-mm (0.86-in), which is 33% of the diameter of a soft drink can (21.8-mm/66-mm). Obviously, it is impractical to fit a carrier, mechanical gears or belts and an electrical power system, of sufficient strength and durability to drive a rapidly rotating cutting wheel, within 33% of the diameter of a soft drink can. Accordingly, U.S. Pat. No. 6,478,093 B1 is silent to a viable means of longitudinally cutting a common API 2⅜″ tubing conduit with anything other than the disclosed chemically reactive longitudinal cutter.
Additionally, e.g., U.S. Pat. No. 3,749,187, U.S. Pat. No. 6,615,933 B1, US 2013/0299248 A1 and US 2013/0048287 teach downhole tools mountable on a drill string, which are disclosed as casing cutters, under-reamers and/or expandable stabilizers, and which can radially deploy extendable members, such as stabiliser blades or cutters that can use the relative axial movement of a drill string within a large bore hole. However, all of these patents and applications are silent to practically arranging the apparatus to form a longitudinal cut with slickline hoisting string within small diameter tubing.
Alternatively, various prior art disclosures can appear visually similar, despite having an intended purpose contrary to the present invention. For example, e.g., Huntings International provides a conventional slickline anti blow-up tool and Clapp et al. (US 2013/0092372 A1) teaches an anti-blow-up device or brake that is suitable for preventing tool strings from being blown up-hole inadvertently by fluid flow that can appear visually similar to the embodiments of the present invention, but which teach and serve a contrary purpose.
Additionally, various combinations of prior art are illogical and, therefore, are not part of a logically combinable state of the art. For example, someone skilled in the art would not consider combining a tool used to clean a surface with a tool used to destroy the surface because they serve contrary purposes. Like virtually every mechanical device of any complexity, the present invention can use wheels, springs, pistons and other common components. For example, the present invention can use a cutting wheel that can allow rotation of the cutting edge, whereby said rotation is a frictional improvement but not a requirement of a draggable cutter arrangement of the present invention that provides a greater overall benefit than the sum of the benefits associated with the parts used.
Prior art of the present inventor, e.g. U.S. Pat. No. 8,387,693, GB 2471760, GB 2484166, GB 2486591 and GB 2492663, which is silent to bascule and arcuate linkages disclosed herein, can be adapted for use within the scope and spirit of the present invention, wherein, e.g., the milling of a surface may be significantly improved or avoided through wall cultivation, and wherein various furrow like tracks produced by a reactive torque tractor of the present inventor can be adapted to furrow cut walls surrounding an innermost passageway through arcuate engagement linkage adaptations that extend the tractor's wheels to a secondary wall surface.
Conventional and prior art cementing wiper plugs can be used to urge cement through a casing, or to urge cement through perforations within a casing, provided the wiper plug is sized for the casing, but even an adjustable size wiper plug is generally unsuitable for squeezing cement through and around a non-uniform wall surface. For example, US 2012/0285696 A1 is silent to squeezing cement and making large changes in size between, e.g., 60 millimeter (mm) or 2⅜ inch (in.) tubing and large casings, such as 244.5 mm (9⅝ in.) and 339.7 mm (13⅜ in.), as the plug is pumped through the changes in internal diameter.
Conversely, a low amplitude intrusion and/or spreading scraping member of the present invention, comprising, e.g., an adapted pedal basket with secured abrasive cutters and/or flexible arcuate pedals, can be used to scrape and separate wall surface furrows and/or perforations and squeeze, e.g., cement or resin into the wall surface furrows and/or perforations to force cement behind a wall for sealing or to grout the furrows or perforation holes and/or perforation cuts into or through a wall surface to prepare the surface for use by, e.g., an open hole or cased hole inflatable packer.
Cultivation of a surface of a wall of a well bore, conduit or cable can comprise, e.g., primary cutting using a scraper member to provide cutting or tillage and/or secondary scraping cultivation to smooth resulting rough wall surfaces and/or apply or squeeze a spreadable substance across or into a wall surface in preparation for engagement of ancillary downhole equipment or other spreadable substances and/or linings to the wall surface. Conventional apparatus and prior art can be adapted to perform the first or primary and second or secondary features of cultivating a subterranean wall surface. It is important to adapt an apparatus so as to inhibit or prevent the burying of the apparatus within the wall surface during cultivation, wherein it can be selectively arranged to, e.g., form a non-binding furrow cut that can alleviate the propensity for pinching during knife blade cuts according the concave shape of said furrow.
The convention of attempting surgical precision, non-intrusive scraping and/or the complete destruction of a wall surface can cause unnecessary complexities resulting in tool sticking and/or tool failure within the downhole environment due to various contrary well elements comprising, e.g., a relatively strong circular shape formed by steel casing, cement and a surrounding non-homogeneous strata bore that can fracture or be comprised of unconsolidated minerals that are affected and decay at different rates during attempts to make precise cuts. Casing or tubing steel is purposely made to be resistant to cutting and intrusion into or severance of its wall surfaces, whereas cement and strata are significantly weaker. Additionally, downhole cables can quickly become tangled around downhole tools attempting to perform a task which can also lead to sticking and/or tool failure.
The problem of downhole intervention is further complicated by differing perspectives within the industry. For example, major service providers are positively incentivised by complexity and downhole problems because their profits are more apt to increase with increased complexity and hole problems than with simplicity and the lack of hole problems. Conversely, operators or producers must pay for complexity and hole problems and are, hence, incentivised to find simpler and more cost effective means. Prior to the consolidation of service providers initiated by the oil price crash of 1986, the service industry was very competitive and relatively efficient; unfortunately, the industry now faces an oligopolistic services industry that lacks the necessary competitive forces to be truly efficient and, as a result, the search for simpler and more cost effective methods and apparatus suffers.
The art of downhole wall surface preparation was initially simple and began with the use of ropes and cables, but has since progressed to more complex rotary drill pipe operations. The present invention amalgamates the lessons of other arts comprising, e.g. a horticultural weed trimmer, with the advances within the well conduit cutting art, e.g. super abrasive filament strands, to provide method and apparatus usable to provide simpler and more cost effective downhole wall surface preparation.
Prior art discloses the genus of wall surface preparation, but it does not anticipate the species of downhole surface cultivation, which is comparable to surface cultivation, and which can be used to prepare a wall surface for engagement by ancillary equipment or substances. Prior art is silent to subterranean wall surface cultivation, which can, e.g., use a bascule or filament arrangement and/or a furrow's shape to reduce a cut's precision while limiting the necessary area of wall surface removal. Accordingly, the present invention cannot be anticipated from prior art with sufficient specificity to solve the industry problems described herein.
Serious downhole problems can relate to tangling, sealing and/or sticking during severance which can be caused by the application of tension or compression associated with axial movement, or torque associated with axial rotation, whereby the resistance of steel tubing and casing to cutting, axial movement and/or axial rotation combined with the inclusion of cables necessary for various downhole operations involving valves, gauges and/or other downhole equipment, can cause conventional and prior art to be ineffective when, e.g., tools become stuck downhole.
Other cutting, sealing and/or removal problems can relate to a dichotomy of two or more materials, wherein the strength of various well elements associated with the circular shapes, diameters, depths and the location of bores, conduits and/or cables, relative to each other, that can cause a combination of problems that can inhibit or prevent access within a well and which can be very difficult to cost effectively solve.
A need exists for a simpler and improved removal of all or portions of a surface of a wall of a well bore, a conduit, or a cable using more reliable cutting or severance methods and apparatus that can be used across a combination of one or more well bores, conduits and/or cables of varying material strength.
Problems relating to excessive vibration and equipment failure, which can occur during the milling or cutting of bore, conduit and/or cable wall surfaces can cause tool failure and stuck equipment, which can prevent rig-less milling and cause problems for drilling rigs, which must remove a well's protective barriers to perform such work.
A need exists for improved milling operations, wherein such operations can benefit from first cultivating a subterranean wall surface prior to said milling or other secondary operations. A further need exists for replacing downhole milling with a simpler and less costly means, which is reliable and usable with rig-less operations when, e.g., sealing of the lower end of the well bore is required during, e.g., suspension, side-tracking and abandonment.
Other well surface preparation problems can relate to open hole side-tracks where kicking off of a cement plug to drill a branch from a suspended or abandoned main bore can be difficult and require several costly attempts when bottom hole assemblies (BHA's) tend to migrate away from harder rock and back into softer cement within the original bore, particularly when practitioners are uncertain as to how long to wait, or standby operations are perceived to be too costly to wait, for the complete curing of settable cement.
A further need exits for reducing the costs of surface preparation by: (i) reducing the complexity of wall surface preparation; (ii) demonstrating an easier approach to operators which overcomes the service company prejudice toward the profits associated with hole problems; (iii) providing and/or adapting conventional and prior art tools, according to the scope and spirit of the present invention, for use during cultivation; and iv) providing relatively small diameter tools that can be effectively used to change from a small diameter to a larger diameter within well bores and conduits to reduce the service company's investment in tools, spares and off-the-shelf variations so as to lower the cost of downhole wall surface preparations for operators while increasing service company profits.
The question being answered by the present invention is how the presently complex operation of subterranean wall surface preparation can be made simpler. Historically, the complex problems of subterranean wall surface preparation has not prompted skilled persons to modify or adapt the closest prior art because, despite having the means to cut rock and steel, persons skilled in the art of subterranean wall surface preparation are not skilled in the art of cultivation whereby it is perceived that rock and steel are too hard and too dense to apply the art of cultivation.
A simpler means of cutting cables and/or rig-lessly milling wall surfaces within a well is needed because cables can cause serious issues comprising, e.g., leak paths and/or the tangling and sticking of tools, which is costly and can be dangerous, while the vibrations caused by milling can be equally problematic with the destruction and/or sticking of downhole tools. Combining the teachings of the art of cultivation with subterranean wall surface preparation has not, generally, been afforded a reasonable expectation or likelihood of success because longitudinal cuts along a well bore are generally not practiced and a single transverse cut across a well bore can be complex enough without undertaking numerous transverse longitudinal cuts. Surprisingly, however, once the problem is formulated and overcome using flexible arcuate engagements it becomes easy to see how the practice of primary and secondary cultivation can be applied to various complex problems to simplify and alleviate them.
It is not the practice within an oligopolistic services market, where 75% of the service market is controlled by four companies, to carry out experiments with adaptations of simple and low profit margin downhole equipment to determine alternatives to the perceived higher profit ways of overcoming the problems of a real or imagined technical obstacle. The adaptation of cultivation to a subterranean wall surface has the surprising result that, e.g., cutting furrows with a flexible arcuate scraper can cut through various materials and prevent tool sticking through a furrow like shape or by disposal of a part of a cutter, e.g. an abrasive filament, downhole while the dislodging of debris to form wall surface regions can be usable to treat and/or avoid milling entire wall surfaces.
Various embodiments are disclosed so as to be appreciated by persons in the arts of downhole tool adaptation and/or use, wherein only the details necessary for elucidating various solutions, which lay outside of conventional practice or the art of downhole wall preparation, are provided. Various aspects of the present invention lie in realizing what the problem is, e.g. using a less precise and less intrusive form of wall penetration and/or preparation that, once realized, may be obvious, and whereby the solution may, in practice, involve minimal apparatus adaptation and/or method steps. Accordingly, adaptions for the subterranean cultivation of a wall surface could not have been obvious prior to disclosure, otherwise such cultivation would have been taught within prior art and conventionally practiced.
A need exists for a means of cutting that is intermediate to conventional severance and conventional milling, wherein the controlled slicing or slot cutting in or through one or more of the surfaces of a wall of a well bore, conduit, and/or cable can be cost effectively implemented without a significant risk of becoming pinched by, or stuck within, the edges of the wall surface cut.
A need exists for cutting and/or avoiding tangling within downhole cables during the treatment of various wall surfaces, which may comprise strata, cement and/or metal and which can have either relatively thin walls or relative thick walls with a variety of surfaces and materials, wherein significant benefit is realized by using a smaller number of tools that can be used extended and retracted from a relatively small diameter to a relatively large diameter for engagement to and disengagement from a wall surface during treatment of the wall surface.
A need exits for removing the necessity of milling operations or an improvement to such milling operational procedures by first cultivating a wall surface to reduce the vibration and improve the efficiency of milling, reaming and under reaming operations and jointed and coiled string operations from drilling rigs and rig-less arrangements.
A need exists for improved preparation of wall surfaces and cementing within open hole suspension, abandonment and side-tracks. A further and related need exists for improvements in setting cement plugs, improvements in the strength of cement plugs and improvements in securing cement to strata and/or casing.
A related and significant need exists for providing improved and/or more efficient means of sealing wells by squeezing cement into perforations, fractures and/or proppant fractures formed by the proliferation of shale gas and tight sand development that purposely fracture rock formations and insert proppant to prevent the rock fracture from closing and sealing, which make the rock significantly more productive and exponentially harder to seal at the end of a well's economic life, when flow from the fractures can represent an environment and safety concern.
Small diameter well intervention and wall surface preparation tools, necessary to cost effectively access many wells, can lack sufficient metal thickness and associated strength to expand from small diameters of tubing to the large diameters of casing, whereby the variety of tool sizes and tool spare part inventories necessary for each conventional tubing and casing size are expensive to build and maintain.
A need exists for small diameter tools of sufficient metal thickness and strength to cut wall surfaces longitudinally and/or transverse to the longitudinal axis of a well by expanding from a smaller diameter commonly used for tubing to a larger diameter commonly used casing to reduce the cost of building and maintaining a tool set capable of wall surface treatment.
A related need exists for more efficient and cost effect subterranean wall surface preparation that can reduce costs for operators and provide service profit through simplicity, ease of implementation and the universal sizing and minimization of tool inventories and tool spare part inventories.
Various aspects of the present invention address these needs.